In a semiconductor device manufacturing process, various vacuum processes such as a film forming process and an etching process are performed on a semiconductor wafer as a processing target substrate (hereinafter, simply referred to as a “wafer”) in a vacuum atmosphere. Recently, in order to improve efficiency of the vacuum process and suppress oxidation or contamination, there has been used a multi-chamber vacuum processing system of a cluster tool type. In the multi-chamber vacuum processing system, a multiple number of vacuum processing units are connected to a transfer chamber which is maintained in a vacuum state and the wafer is transferred into each of the vacuum processing units by a transfer device which is provided in the transfer chamber (see, for example, Patent Document 1).
In such a multi-chamber processing system, in order to transfer the wafer from a wafer cassette which is placed in an atmosphere state into the transfer chamber which is maintained in the vacuum state, a load lock device (load lock chamber) is provided between the transfer chamber and the wafer cassette. The wafer is transferred via the load lock device.
Meanwhile, when a high-temperature process such as a film forming process is performed in this multi-chamber processing system, the wafer may be taken out of the vacuum processing unit and transferred into a vessel in the load lock device while a wafer temperature becomes a high temperature over, e.g., about 500° C. If, however, the wafer having such a high temperature is exposed to the atmosphere, the wafer may be oxidized. Further, if this high-temperature wafer is accommodated in an accommodation vessel, the accommodation vessel, which is typically formed of a resin, may be damaged.
In order to solve these problems, a cooling plate having a cooling device for cooling the wafer is provided within the vessel of the load lock device. The wafer is placed close to the cooling plate, and the wafer is cooled by the cooling plate while an inside of the load lock device is returned back to an atmosphere state from the vacuum state.
Patent Document 1: Japanese Patent Laid-open Publication No. 2000-208589